Allied Telesis AR400 Explanation of IGMP filtering controlling multicast distribution, Received

IGMP filtering (controlling multicast distribution) > Explanation of IGMP filtering (controlling multicast distribution)

Explanation of IGMP filtering (controlling multicast distribution)

Immediately after applying the filter, we check the group entries on switch 1 by using the command show ip igmp, and see that the switch still has an entry for the group we are filtering out.

Manager Switch 1> show ip igmp

IGMP Protocol

------------------------------------------------------------------------

Status	Enabled
Default Query Interval	125	secs
Default Timeout Interval	260	secs
Last Member Query Interval	10 (1/10secs)
Last Member Query Count	2
Robustness Variable	2
Query Response Interval	100	(1/10secs)
Disabled All-groups ports	None

Interface Name	vlan100	(DR)
Group List
Group. 224.0.1.22	Last Adv. 172.31.0.99	Refresh time 192 secs
Ports 1

------------------------------------------------------------------------

This entry is still there because the switch had previously received a report for the group. Since applying the filter, there have not been any messages for the group, so the switch has not yet filtered the group out. We can see this by using the command show igmp filter to check the number of processed messages.

Manager Switch 1> show igmp filter=1

IGMP	Filters
------------------------------------------------------------------
No.	Entry	Group Address		Action	Matches
------------------------------------------------------------------
1	1	224.0.1.22	224.0.1.22	Exclude	0
	2	224.0.0.0	224.255.255.255	Include	0
Received: 0			Passed: 0	Dropped: 0

------------------------------------------------------------------------

Page 38 AlliedWare™ OS How To Note: IGMP